const wu = require("./wuLib.js");
const path = require("path");
const fs = require("fs");
const {VM} = require('vm2');
const cssbeautify = require('cssbeautify');
const csstree = require('css-tree');
const cheerio = require('cheerio');

function doWxss(dir, cb, mainDir, nowDir) {
	let saveDir = dir;
	let isSubPkg = mainDir && mainDir.length > 0;
	if (isSubPkg) {
		saveDir = mainDir
	}

	function GwxCfg() {
	}

	GwxCfg.prototype = {
		$gwx() {
		}
	};
	for (let i = 0; i < 300; i++) GwxCfg.prototype["$gwx" + i] = GwxCfg.prototype.$gwx;
	let runList = {}, pureData = {}, result = {}, actualPure = {}, importCnt = {}, frameName = "", onlyTest = true,
		blockCss = [];//custom block css file which won't be imported by others.(no extension name)
	let commonStyle = {};//some global css
	function cssRebuild(data) {//need to bind this as {cssFile:__name__} before call
		let cssFile;

		function statistic(data) {
			function addStat(id) {
				if (!importCnt[id]) importCnt[id] = 1, statistic(pureData[id]);
				else ++importCnt[id];
			}

			if (typeof data === "number") return addStat(data);
			if (data != undefined) {
				for (let content of data) if (typeof content === "object" && content[0] == 2) addStat(content[1]);
			}
		}

		function makeup(data) {
			var isPure = typeof data === "number";
			if (onlyTest) {
				statistic(data);
				if (!isPure) {
					if (data.length == 1 && data[0][0] == 2) data = data[0][1];
					else return "";
				}
				if (!actualPure[data] && !blockCss.includes(wu.changeExt(wu.toDir(cssFile, frameName), ""))) {
					console.log("Regard " + cssFile + " as pure import file.");
					actualPure[data] = cssFile;
				}
				return "";
			}
			let res = [], attach = "";
			if (isPure && actualPure[data] != cssFile) {
				if (actualPure[data]) return '@import "' + wu.changeExt(wu.toDir(actualPure[data], cssFile), ".wxss") + '";\n';
				else {
					res.push("/*! Import by _C[" + data + "], whose real path we cannot found. */");
					attach = "/*! Import end */";
				}
			}
			let exactData = isPure ? pureData[data] : data;
			if (typeof data === 'string') {
				let styleData = commonStyle[data]
				let fileStyle = ''
				if (styleData != undefined) {
					for (let content of styleData) {
						if (typeof content === 'string') {
							if (content != '1') {
								fileStyle += content
							}
						} else {
							if (content.length != 1) {
								fileStyle += content[1] + 'rpx'
							}
						}
					}
				}
				exactData = fileStyle
			}
			for (let content of exactData)
				if (typeof content === "object") {
					switch (content[0]) {
						case 0://rpx
							res.push(content[1] + "rpx");
							break;
						case 1://add suffix, ignore it for restoring correct!
							break;
						case 2://import
							res.push(makeup(content[1]));
							break;
					}
				} else res.push(content);
			return res.join("") + attach;
		}

		return () => {
			cssFile = this.cssFile;
			if (!result[cssFile]) result[cssFile] = "";
			result[cssFile] += makeup(data);
		};
	}

	function runVM(name, code) {
		let wxAppCode = {}, handle = {cssFile: name};
		let vm = new VM({
			sandbox: Object.assign(new GwxCfg(), {
				__wxAppCode__: wxAppCode,
				setCssToHead: cssRebuild.bind(handle),
				$gwx(path, global) {

				}
			})
		});

		// console.log('do css runVm: ' + name);
		vm.run(code);
		for (let name in wxAppCode) {
			handle.cssFile = path.resolve(saveDir, name);
			if (name.endsWith(".wxss")) {
				wxAppCode[name]();
			}
		}
	}

	function preRun(dir, frameFile, mainCode, files, cb) {
		wu.addIO(cb);
		runList[path.resolve(dir, "./app.wxss")] = mainCode;

		for (let name of files) {
			if (name != frameFile) {
				wu.get(name, code => {
					code = code.replace(/display:-webkit-box;display:-webkit-flex;/gm, '');
					code = code.slice(0, code.indexOf("\n"));
					if (code.indexOf("setCssToHead(") > -1) {
						let lastName = name;
						let dirSplit = name.split(nowDir + '/');
						if (dirSplit.length > 1) {
							lastName = path.resolve(saveDir, dirSplit[1]);
						}
						runList[lastName] = code.slice(code.indexOf("setCssToHead("));
					}
				});
			}
		}
	}

	function runOnce() {
		for (let name in runList) runVM(name, runList[name]);
	}

	function transformCss(style) {
		let ast = csstree.parse(style);
		csstree.walk(ast, function (node) {
			if (node.type == "Comment") {//Change the comment because the limit of css-tree
				node.type = "Raw";
				node.value = "\n/*" + node.value + "*/\n";
			}
			if (node.type == "TypeSelector") {
				if (node.name.startsWith("wx-")) node.name = node.name.slice(3);
				else if (node.name == "body") node.name = "page";
			}
			if (node.children) {
				const removeType = ["webkit", "moz", "ms", "o"];
				let list = {};
				node.children.each((son, item) => {
					if (son.type == "Declaration") {
						if (list[son.property]) {
							let a = item, b = list[son.property], x = son, y = b.data, ans = null;
							if (x.value.type == 'Raw' && x.value.value.startsWith("progid:DXImageTransform")) {
								node.children.remove(a);
								ans = b;
							} else if (y.value.type == 'Raw' && y.value.value.startsWith("progid:DXImageTransform")) {
								node.children.remove(b);
								ans = a;
							} else {
								let xValue = x.value.children && x.value.children.head && x.value.children.head.data.name,
									yValue = y.value.children && y.value.children.head && y.value.children.head.data.name;
								if (xValue && yValue) for (let type of removeType) if (xValue == `-${type}-${yValue}`) {
									node.children.remove(a);
									ans = b;
									break;
								} else if (yValue == `-${type}-${xValue}`) {
									node.children.remove(b);
									ans = a;
									break;
								} else {
									let mValue = `-${type}-`;
									if (xValue.startsWith(mValue)) xValue = xValue.slice(mValue.length);
									if (yValue.startsWith(mValue)) yValue = yValue.slice(mValue.length);
								}
								if (ans === null) ans = b;
							}
							list[son.property] = ans;
						} else list[son.property] = item;
					}
				});
				for (let name in list) if (!name.startsWith('-'))
					for (let type of removeType) {
						let fullName = `-${type}-${name}`;
						if (list[fullName]) {
							node.children.remove(list[fullName]);
							delete list[fullName];
						}
					}
			}
		});
		return cssbeautify(csstree.generate(ast), {indent: '    ', autosemicolon: true});
	}

	wu.scanDirByExt(dir, ".html", files => {
		let frameFile = "";
		if (fs.existsSync(path.resolve(dir, "page-frame.html")))
			frameFile = path.resolve(dir, "page-frame.html");
		else if (fs.existsSync(path.resolve(dir, "app-wxss.js")))
			frameFile = path.resolve(dir, "app-wxss.js");
		else if (fs.existsSync(path.resolve(dir, "page-frame.js")))
			frameFile = path.resolve(dir, "page-frame.js");
		else throw Error("page-frame-like file is not found in the package by auto.");
		wu.get(frameFile, code => {
			code = code.replace(/display:-webkit-box;display:-webkit-flex;/gm, '');
			let scriptCode = code;
			//extract script content from html
			if (frameFile.endsWith(".html")) {
				try {
					const $ = cheerio.load(code);
					scriptCode = [].join.apply($('html').find('script').map(function (item) {
						return $(this).html();
					}, "\n"));
				} catch (e) {
					//ignore
				}
			}

			let window = {
				screen: {
					width: 720,
					height: 1028,
					orientation: {
						type: 'vertical'
					}
				}
			};
			let navigator = {
				userAgent: "iPhone"
			};

			scriptCode = scriptCode.slice(scriptCode.lastIndexOf('window.__wcc_version__'));
			let mainCode = 'window= ' + JSON.stringify(window) +
				';\nnavigator=' + JSON.stringify(navigator) +
				';\nvar __mainPageFrameReady__ = window.__mainPageFrameReady__ || function(){};var __WXML_GLOBAL__={entrys:{},defines:{},modules:{},ops:[],wxs_nf_init:undefined,total_ops:0};var __vd_version_info__=__vd_version_info__||{}' +
				";\n" + scriptCode;

			if (code.indexOf('__COMMON_STYLESHEETS__') != -1) {
				let commonStyles = code.slice(
					code.indexOf('__COMMON_STYLESHEETS__||{}') + 26,
					code.indexOf(
						'var setCssToHead = function(file, _xcInvalid, info)'
					)
				)
				commonStyles =
					';var __COMMON_STYLESHEETS__ = __COMMON_STYLESHEETS__||{};' +
					commonStyles +
					';__COMMON_STYLESHEETS__;'
				commonStyle = new VM().run(commonStyles)
			}

			//remove setCssToHead function
			mainCode = mainCode.replace('var setCssToHead = function', 'var setCssToHead2 = function');

			code = code.slice(code.lastIndexOf('var setCssToHead = function(file, _xcInvalid'));
			code = code.replace('__COMMON_STYLESHEETS__', '[]');

			if (code.indexOf('_C =') == -1) {
				code = code.slice(code.lastIndexOf('\nvar _C= ') + 1);
			} else {
				code = code.slice(code.lastIndexOf('\nvar _C = ') + 1);
			}

			code = code.slice(0, code.indexOf('\n'));
			let vm = new VM({sandbox: {}});
			pureData = vm.run(code + "\n_C");

			console.log("Guess wxss(first turn)...");
			preRun(dir, frameFile, mainCode, files, () => {
				frameName = frameFile;
				onlyTest = true;
				runOnce();
				onlyTest = false;
				console.log("Import count info: %j", importCnt);
				for (let id in pureData) if (!actualPure[id]) {
					if (!importCnt[id]) importCnt[id] = 0;
					if (importCnt[id] <= 1) {
						console.log("Cannot find pure import for _C[" + id + "] which is only imported " + importCnt[id] + " times. Let importing become copying.");
					} else {
						let newFile = path.resolve(saveDir, "__wuBaseWxss__/" + id + ".wxss");
						console.log("Cannot find pure import for _C[" + id + "], force to save it in (" + newFile + ").");
						id = Number.parseInt(id);
						actualPure[id] = newFile;
						cssRebuild.call({cssFile: newFile}, id)();
					}
				}
				console.log("Guess wxss(first turn) done.\nGenerate wxss(second turn)...");
				runOnce()
				console.log("Generate wxss(second turn) done.\nSave wxss...");

				console.log('saveDir: ' + saveDir);
				for (let name in result) {
					let pathFile = path.resolve(saveDir, wu.changeExt(name, ".wxss"));
					wu.save(pathFile, transformCss(result[name]));
				}
				let delFiles = {};
				for (let name of files) delFiles[name] = 8;
				delFiles[frameFile] = 4;
				cb(delFiles);
			});
		});
	});
}

module.exports = {doWxss: doWxss};
if (require.main === module) {
	wu.commandExecute(doWxss, "Restore wxss files.\n\n<dirs...>\n\n<dirs...> restore wxss file from a unpacked directory(Have page-frame.html (or app-wxss.js) and other html file).");
}
